Railway brake



Feb. 1%. 1935'.

w. J. s rrH RAILWAY BRAKE Original Filed May a, 1920 JQSQVENTOF ATTORNEY Patented Feb. 17, 1925.

HUDSON SMITH,

PATENT OFFICE.

OF ST, PAUL, MINNESOTA.

RAILWAY BRAKE.

Original applioationhfiled May 8, 1920, Serial No. 379,730. Divided and this application filed August To aZZwlwm it mag concern;

Be it known that i, I, Wnmmu. JUosoN. SMITH, a citizen of thellnited States, re sidingat St. Paul, in the county of Ramsey and State of Minnesota, have. invented cert tainnew and useful Improvements in Railway Brakes, of which the following is a full,

clear, and exact description, such as will. enable others skilled in theart to which it appertains to make and use thesame.

This invention relates to. braking means videan improved braking mechanismwhich avoids wear on, the truck wheels and avoids failures in the latter which often occur due 1 to improper functioning of the brake shoes.

It is a further object of the invention to provide an improved braking mechanism mechanismrwhich is relatively light in weight, iQlIlOlBIlt. in, operation and quick in automaticrelease.

Another object is to provide an improved brakingumechanism of the .drum and band type having an. especially large friction contact? area and wherein the wear on the parts is evenly distributed.

It is another object of the invention to provide an improved brakingmechanism especially adapted for use with street railway car and other railway trucksipossessing fea-' tures of structural superiority and functional advantage.

Otherobjects will be in part obvious and in part pointed out hereinafterv In the accompanying drawings which illustrate a preferred embodiment of the invention,

Figure 1 is. a plan view of a truck pro- 5 vided with the improved braking means;

and

Fig. 2 is a side view of the same, the wheels and obstructing frame parts being broken away for clearness.

The general construction of the truck shown in th drawings comprises a truck bolster 1 having a center bearing 2, a truck frame 3,journal boxes 4, axles 5, and wheels 6. The truck frame includes side frame members 7 joined by transverse end pieces Serial No. 490,198.

8 8 and by transom members 9, 9. In thetruck shown, load stresses are transmitted from the bolster 1 to the side frames 7 through doubleielliptic springslO by means of suitable connections, and from the frames to the axles through thejournal boxes 1. The general truck construction is fully described. in said prior application and a more detailed description thereof herein is considered unnecessary.

The present invention concerns an improved braking mechanism for car trucks in which brake 'bandsare applied to brake drums carried by the axles. In the embodiment of the invention shown in the drawing, a single brake-drumll having a relatively large braking surface on its periphery is rigidly mounted on each axle 5 so as to rotateitherewith. This drum is supplied with a friction brake band 12 which is arranged to engage with the periphery of the drum throughout nearly 860 thereof.

Improved means for applying and releasing said brake band is also provided. As shown in the drawings, the brake band operating means comprises bell-crank levers 13 and 13, the short arm of each of which is pivoted to a bracket 14 mounted on the up per end of the brake band, the otheror long arm being connected to the brake actuating mechanism, Pivotally connected at one end to the elbow of the bell-crank lever is a link 15. slidably supported in an opening in the angularly disposed flange 16 of a bracket or casting 17 the latter being suitably mounted in position adjacent the truck column 18 upon one of thetransoms 9 and truck sides frame-7. The other end of the link 15 extends, through an opening in a bracket or casting 19 secured to the other end of the brake band 12, and is held in cooperative relationship with said bracket by a nut threaded on theend of said link. A spiral spring 20 surrounds the lower end of said link 15, at one end abutting the bracket 19 and at the other end abutting the angularly disposed flange 16 whereby the brake band is yieldingly held in released position;

Adjustable nuts 15 are threaded on the link ing effort for a minimum of weight and size of the parts of the braking mechanism.

Each brake band is supported at a oint opposite the connection thereof to its t1ght ening means by a depending link 21 secured by a set screw in an elongated slot formed in a bracket 22 which is riveted or otherwise suitably secured to the brake band. This link 21 is suitably secured at its upper end to a depending flange of the cross piece or sill 8, 8.

Each bell-crank lever 13 is operated by suitable means to apply the brake, and as shown in the present embodiment, this means comprises a brake rod 23 extending forwardly to a suitable hand or power braking mechanism. This braking mechanism may be of any standard construction, forms no part of the present invention, and need not be further described. The other end of the brake rod is pivotally secured to an equalizing bar 24 intermediate the ends thereof, preferably at its center of length. At one end this bar is fitted with a clevis 25 which is pivotally connected thereto and bifurcated at one end to receive the upper end of the long arm of the bell-crank lever 13, to which it is pivotally connected as at 26. The opposite end of the clevis 25 is supplied with a lug 2'? having an aperture therein to receive the end of a coiled tension spring 28, the opposite end of which is adjustably secured by a threaded eye bolt 29 to a bracket 30 mounted on the transom 9.

The other end of the equalizing bar 24 is also fitted with a clevis 31 pivotally connected thereto, and a flexible member such as a chain 32, is attached at one end to said clevis and extends approximately in a horizontal direction around a horizontally disposed sheave mounted in a bracket 33 on the end piece 8, the end of the backwardly extending portion being connected to a clevis 3- at the upper end of the long arm of the bell-crank lever 13. Also connected at one end to the clevis 34 is a second coiled tension spring 35, the opposite end of which is connected by suitable adjustable means to a bracket 35 secured on the transom 9. This adjustable means may conveniently comprise a threaded eye bolt passing through said bracket and having nuts to hold and lock the same in adjusted position.

The operation of the braking mechanism which will be obvious from the above description may be briefly described as follows:

lVhen a brake is to be applied, a pulling stress is applied to the brake rod 23 and this stress is transmitted to the bell-crank levers 13, 13 through the equalizing bar 2 1 and the connections therefrom as clescribed above, the stress from the equalizing bar to the lever 13 being reversed by means of the chain and sheave connection. Thus the bell-crank levers will be moved against the resistance of compression springs 20 to pull the adjacent ends of the brake band together to the drum and apply the brake. l Yhen the braking force is removed from the brake rod 23 the braking elements are urged to off position by means of the releasing springs 28 and 35, and this action is also assisted by the expansion of band releasing springs 20.

It will be understood that any desirable number of brake drums might be employed in association with each axle. It is found in practice, however, that a single brake drum of comparatively large dimensions is preferable as it provides a lighter, more compact and more economical braking mechanism.

As many changes could be made in the above construction and many apparently widely different embodiments of this in vention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is i 1. In a truck, in combination, an axle and a braking drum thereon, friction means and means for applying the same to retard said drum, said last mentioned means including a bar and a brake rod connected intermediate the ends thereof, a bell-crank lever, means for connecting one end of said bar to one arm of said bell-crank lever, and resilient means connected to said bar for releasing said friction means.

2. In a braking means for trucks, in combination, truck axles, braking drums on said axles and brake bands therefor, an equalizing bar, a brake rod pivotally connected intermediate the ends thereof, connecting means between one end of said equalizing bar and the ends of one of said brake bands, connecting means between the other end of said equalizing bar and the ends of the other of said brake bands including a flexible member and a sheave therefor, and resilient means for releasing said brake bands.

3. In a railway truck, the combination with a truck frame having side trusses, transverse axles each extending at opposite sides of the truck frame beyond the said trusses and carrying flanged wheels disposed outside of said trusses, of brake drums on said axles disposed inside of said truss frames, a brake band for each of said brake drums, an equalizing bar, a lever connected to one end of each of said brake bands and to each end of said equalizing bar, a link connected to each of said levers and to the opposite end of the corresponding brake band, and brackets carried by said truck frame and adjustably supporting said links.

4. In a railway truck, the combination with a truck frame having side trusses, transverse axles each extending at opposite sides of the truck frame beyond the said trusses and carrying flanged wheels disposed outside of said trusses, of brake drums on said axles disposed inside of said truss frames, a brake band for each of said brake drums, an equalizing bar connected at one end to one of said brake bands, a sheave, a flexible connection extending around said sheave and being connected with the opposite end of said equalizing bar and with another of said brake bands.

5. In a railway truck, the combination with a truck frame having side trusses, transverse axles each journaled in and extending at opposite sides of the truck frame and carrying flanged wheels, brake drums on said axles, an equalizing bar, friction means adapted substantially to encircle said brake drums, actuating levers operatively connected to draw said friction means into engagement with said brake drums, said levers having actuating connections leading to said equalizing bar, and brackets carried by said truck frame and adapted to support said levers and friction means in operative relation to said brake drums.

In testimony whereof I affix my signature, in the presence of two witnesses.

WILLIAM J UDSON SMITH. lVitnesses E. N. LEAF, C. S. THoMsoN. 

